Mapping between logical space and physical space is a classic topic of computer science. Mapping can provide virtualization to non-continuous physical space. With the virtualization, the following benefits can be obtained: several isolated continuous logical spaces, each space starting at the same logical address; in combination with the on-demand allocation or thin provisioning technology, a total logical capacity larger than the physical capacity can be obtained. Generally, the address mapping table is used to record the mapping relation between the logical block address and physical block address. As the address mapping table is usually large, it is stored on a non-volatile storage device, which is not easy for quick access.